Flow-control valve assemblies are used to provide a substantially constant fluid flow rate over a range of varying line pressures. Applications which employ flow-control valve assemblies include, without limitation, drinking fountains, beverage dispensers, automatic washing machines for clothes or dishes, hydraulic and pneumatic systems, automotive fuel injectors, and pneumatic machine tools.
A known design of a flow-control valve assembly includes a flow control positioned in a valve body, wherein the flow control has a central through passage, and wherein the valve body includes a bypass flow channel. The flow control includes an upstream top surface, a downstream bottom surface, and an outer cylindrical surface. The downstream bottom surface has longitudinally-projecting, resilient feet. The outer cylindrical surface has an annular seal which projects radially outward from the outer cylindrical surface. Fluid flows through the central through passage under a low and a high fluid pressure. When the top surface of the flow control is subjected to a low fluid pressure, the feet provide a stand-off allowing bypass flow. When the top surface of the flow control is subjected to a high fluid pressure, the resilient feet collapse, the flow control engagingly slides downstream a distance in the valve body, and the annular seal seats against a shoulder of the valve body preventing bypass flow.
Still, scientists and engineers continue to seek improved flow controls and improved flow-control valve assemblies.